<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="myDiv">Click Me</div>
<script>
    /*
        div#myDiv{Click Me}
    /*
        冒泡:
            - 从上到下
                - document -> html -> body -> div
     */
    
    
</script>
</body>
</html>